Treatment of ores



Patented May '26, 1923.

UNITED STATES PATENT OFFICES;

HENRY W. KAANTA, EL PASO, TEXAS, ASSIGNOR TO AMERICAN SMELTING AND REFINING COMPANY, OF NEW YORK, N. Y., A CORPORATION 01 NEW JERSEY.

TREATMENT or ones.

No Drawing.

To all whom it may concern:

Be it known that I, HENRY W. KAANTA, a citizen of the United States, and resident of El'Paso, in the county of El Paso and State of Texas, have invented certain new and useful Improvements in the Treatment toryto their subsequent treatment by the floatation process.

The invention consists broadly in subject-- ing gold and silver ores in a crushed or finely divided condition to a solution containing a relatively small quantity of an alkalinecyanide for a brief period of time andthen adding a suitable preclpitant to recover any values dissolved by the cyanide and in subjecting "the mixture to a concentration process.

The invention also consists in regulating the quantity of cyanide solution and the period of treatment so as to dissolve any film or coating upon the precious" metal particles without attempting to dissolve any substantial portion of the precious metal content of the ores, thereby avoiding interference with the subsequent treatment of the or s and facilitating the subsequent recovery of the precious metals.

The invention'furtherconsists in the new and novel features of operation and the new and original arrangement and combination of steps in the process hereinafter described and more particularly set forth in the claims.

In carrying out my improved process the ore to be treated is first ground with water in any well known type'of grinding apparatus, for example a ball granulaton Preferably' the ore is ground to a size passing coal tar, which may be addedin suitable quantities depending upon the character of application filed June 11, 1924. Serial No. 719,330.

the ore. It has been found in practice that the addition of two pounds of cyanide per ton of ore will usually give satisfactory results but this amount may be decreased (irincreased according to the ore.

The pulp or ground ore, with the cyanide.

solution and with or without a collectin agent as may be desirable, is then agitated for a period of approximately one-half. to

two hours to bring all of the exposed parti cles of the precious metal in the pulp into intimate contact with the alkaline-cyanide in the solution. Any well known style of agitator may be employed, such as a Pachuca tank or a :Dorr agitator. The exact period of agitation will be determined by the character of the ore and the condition of the precious metals therein, but I have found that an agitation of approximately one hour is usually sufficient to produce satisfactory results.

time, a precipitant is added tothe mixture of pulp and cyanide solution. Anyjw'ell known precipitant may be usedsuch as zinc dust vor aluminum dust; and soluble sulphides or charcoal may be used. Thereu on the mixture with the precipant adde is agitated for a further period of approximately fifteen minute'sto one-half hour in order to combine with any gold or silver which may have been dissolved by the cyanide solution during the preceding period of agitation. The total amount of precipitant is relatively small and approximately one pound or less per ton of'dry ore is sufficient After agitation for a suitable period ofusually to precipitate the precious metal and prevent losses with the cyanide solution. I

The mixture comprising the pulp, the alkaline cyanide and the precipitating agent, and with or without a collectlng agent, may then be concentrated by the floatation rocvess after the addition of a suitable frot ing and. collecting reagent, such as refined pine oil. The floatation process is carried out in the usual manner Without any change or modification by reason of prior treatment by the process herein set forth. By means of my improved processit s possible to treat complex ores containin sulphides of the baser metals or oxidize compounds of the baser metals, such as co er, lead, zinc, iron, etc., with a relative y high recovery of the gold and silver convalues in the solution,

tent and solution to in ess. Also any values of gold and silver;

which may have gone into the solution with the cyanide are recovered by the introduction of the recipitant, which is added to the solution uring the step of agitating and which passes with the pulp to the floatation tank and is recovered by concentration. It

will be evident of course that the ,pine oil vor any othersuita'ble frothing agent may be added during the step of agitating the pulp with the cyanide solution and the precipitant and that various other substitutions, changes and omissions in the several steps of my process and in its operation may be made by those skilled in the art without departing from the spiritof the invention.

I claim as my invention:

1. In the art of recovering precious metals from complex ores, the process which consists in mixing the ground ore with a cyanide solution of a strength sutficient to attack any film or coating upon'the precious metal particles contained in the ore without substantial absorption of the metal particles thereof, adding a precipitant of the precious metals contained in the solution, agitating the mixture with. the precipitant therein and then concentrating the metal constitutents of, the ore and the precipitant.-

2. The process of treating ore that'con tains precious metals which consists in mixmg the crushed ores with a weak cyanide solution to remove any coating or film on the precious metal particles contained in the ore, adding a precipitant to recover any a 'itating the precipiduce reaction of the precipitant with the metals in solution, and

particles, agitating the ore and solution,

adding a precipitant thereto and then concentrating the metal constituents of the ore and the precipitant.

4. The process of treating ores to recover precious metals therefrom which consists in mixing the ore in a finely divided condition with a solution containing not more than two pounds of cyanide for each ton of dry ore being treated, agitating the ore and solution for a eriod of time sufli'cient to remove any coat ng or fllm upon the precious metal, particles contained in the ore, adding a precipitant and then concentrating the metal constituents of the ore and the precipitant by floatatiom 5. In t e treatment of ores containing gold and silver, the process which consistsin subjectingthe ore in a finely dividedcondition to the action of a weak solution of an alkaline cyanide,'agitating the mixtnre for a period of time sufiic ent to re-' move any coating or film on the precious metal particles contained in the ore, adding a precipitant to the mixture, again vagitatdissolved by the cyanide and then concenn trating the metals of the ore and. the pre-- cipitant by floatation. Signed at El Paso, in the county of El Pasoand State of Texas,-this second day of June, 'A. D'., 1924. I

I HENRY W. KAANTA. 

